1. Field of Technology
The embodiments herein relate to an organic light emitting display device and a method for manufacturing the same, and more particularly, to an organic light emitting display with an auxiliary electrode for reducing voltage drops.
2. Description of the Related Art
An organic light emitting display device, as a self-emission display device, does not require a separate light source as a liquid crystal display. The organic light emitting display device is more power efficient and has better response speed, viewing angle, and contrast ratio than the liquid crystal display, making it a promising next-generation display device.
In an organic light emitting display device employing a top emission type organic light emitting element, the light emitted from the organic emission layer exits upward through a transparent or semi-transparent electrode cathode. To obtain sufficient light transmittance rate through the cathode, the cathode needs to be formed very thin. Therefore, the cathode is made of a transparent conductive material such as indium tin oxide (ITO), or magnesium-silver (MgAg) having a sufficiently low thickness so that the cathode is transparent. The decrease in thickness of the cathode, however, increases the surface electrical resistance. The increased electrical resistance, in turn, causes voltage drop (i.e., IR drop) in some parts of the organic light emitting display device, creating non-uniform luminance throughout the screen. The voltage drop phenomenon intensifies as the size of the display device increases. In this specification, the term “voltage drop” or “IR drop” refers to the phenomenon in which a potential difference between the anode and the cathode of the organic light emitting element decreases.
Accordingly, there remains a need for an organic light emitting display device with improved configuration for reducing the voltage drop problem.